The present invention relates to the control of pests such as insects and arachnids and, more particularly, to a nonhazardous pest control agent that eliminates pests through either neural effects of a component or mechanical puncture of the exoskeleton and also, through the neurally effective component entering the puncture.
Insects and other pests have long plagued humankind. Over the years, various approaches have been taken to control pests and especially insects, and none have been completely satisfactory.
For example, the use of complex, organic insecticides, such as disclosed in U.S. Pat. Nos. 4,376,784 and 4,308,279, are expensive to produce, can be hazardous to man, domestic animals, and the environment, and frequently are effective only on certain groups of insects. Moreover, the target insects often build an immunity to the insecticide.
Another approach employs absorbent organic polymers for widespread dehydration of the insects. See, U.S. Pat. Nos. 4,985,251; 4,983,390; 4,818,534; and 4,983,389. However, this approach is limited predominantly to aquatic environments, and it likewise relies on hazardous chemical insecticidal agents. Further, the addition of essential oils is primarily as an insect attractant.
In addition, this approach is based on the selective absorption of a thin layer of insect wax from the exoskeleton and not to a puncture of the exoskeleton. [Sci. Pharm. Proc. 25th, Melchor et al, pp. 589-597 (1966)].
The use of inorganic salts as components of pesticides is reported by U.S. Pat. Nos. 2,423,284 and 4,948,013, European Patent Application No. 462 347, Chemical Abstracts 119(5):43357q (1993) and Farm Chemicals Handbook, page c102 (1987). These references disclose the inclusion of these components but not the puncturing of the exoskeleton of the insect by the salts.
The applicants are also aware of the following which disclose pesticides and insecticides: U.S. Pat. Nos. 4,806,526, 4,834,977, 5,110,594, 5,271,947 and 5,342,630.
The marketplace is replete with toxic chemical insecticidal agents that are offensive to apply and, more importantly, pose a danger to humans and the environment.
It would be greatly advantageous to solve these problems with a pesticidal agent that works neurally and with a penetrating substance to kill pests, thereby eliminating the need for any chemicals which are toxic to humans and domestic animals.
Accordingly, it is an object of the invention to provide a method for non-hazardous pest control and a composition for the same which kills pests neurally and both mechanically and neurally.
It is another object to provide a safe, non-toxic pest control agent that will not harm the environment.
It is another object to provide a pest control agent that is highly effective in combating a wide variety of pests, including al insects and arachnids having an exoskeleton.
If is another object to provide a pest control agent which has either no scent or a pleasant scent, and which can be applied without burdensome safety precautions for humans and domestic animals.
It is still another object to provide a pest control agent as described above which can be inexpensively produced.
It is yet another object of the invention to provide a pest control agent to which pests cannot build an immunity.
In accordance with the above-described and other objects, the present invention provides a pesticide for insects and arachnids comprising a carrier and at least a neurally effective substance. The neurally effective substance has a chemical structure of 
where R1 is any of the following:
CH2, C2H4, C3H6, C3H4, C4H8 or C4H4 
where R2 is any of the following:
H, H2, CH3, C2H5, C3H7, C3H5, C4H9 or C4H5 
where R3 is any of the following:
H, H2 or OCH3 
where the six member ring ABCDEF has at least one unsaturated bond therein.
During the course of developing improved insecticidal compositions the inventors have found that various organic compounds when applied in a novel manner will unexpectedly act as a pesticide to kill insects and arachnids. Among the preferred compounds that applicants have found to be insecticidal are terpeniol, phenylethyl alcohol, benzyl acetate, benzyl alcohol, eugenol and cinnamic alcohol. To be affective these compounds should be incorporated into carriers preferably in the form of aerosols dusts, solutions, liquid emulsions and the like.
The herein disclosed invention envisions a pesticide for insects and arachnids comprising a carrier and an effective amount of at least one neurally effective substance. In a specific embodiment the carrier is crystalline dust having a size effective to puncture the exoskeleton and to permit the neurally effective substance to enter the punctured exoskeleton and interfere with the bodily function of the insects and arachnids. Specifically the carrier can be a crystalline powder of a mixture of alkali metal bicarbonate, calcium carbonate, diatomaceous earth and amorphous silica. The crystalline powder has a particle size of 0.1 to 200 microns, and preferably under 100 microns, and the calcium carbonate can be in the form of ground pottery glaze. In an alternative embodiment the carrier is an aerosol spray having a solvent and a propellant, and is compatible and non-reactive with the neurally effective substance. Specifically the solvent can be an organic solvent, either aromatic or aliphatic, and wherein the propellant is carbon dioxide or dimethyl ether. It is to be understood that the solvent is compatible and nonreactive with the neurally effective substances. The neurally effective substances in the composition can be in the range of approximately 0.01% to 10% by weight of the pesticide composition. In some embodiments of the pesticidal composition the neurally effective substance is a mixture of two or more neurally effective substances and/or other diluents included for aesthetic purposes.
In an alternative embodiment of the pesticide for controlling insects and arachnids the composition comprises an effective amount of crystalline powder including calcium carbonate, alkali metal bicarbonate, absorbent material and at least one neurally effective substance having a chemical structure represented by the formula 
where R1 is any of the following:
CH2, C2H4, C3H6, C3H4, C4H8 or C4H4 
where R2 is any of the following:
H, H2, CH3, C2H5, C3H7, C3H5, C4H9 or C4H5 
where R3 is any of the following:
H, H2 or OCH3, and
where the six member ring ABCDEF has at least one unsaturated bond therein, and also an ester of the hydroxyl group on R1 when R1 is CH2, R2 is H and R3 is H, and specifically an acetate ester. The pesticide formulation contains the neurally effective substance in 0.1 to 10% by weight of the pesticide. The crystalline powder of this composition comprises calcium carbonate 27%-35%, sodium bicarbonate 54%-65% and absorbent material 4%-5% by weight.
In a particularly elegant embodiment of this invention the pesticide for controlling insects and arachnids comprises an aerosol spray including a solvent, a propellant and an effective amount of at least one neurally effective substance having a chemical structure of 
where R1 is any of the following:
CH2, C2H4, C3H6, C3H4, C4H8 or C4H4 
where R2 is any of the following:
H, H2, CH3, C2H5, C3H7, C3H5, C4H9 or C4H5 
where R3 is any of the following:
H, H2 or OCH3, and
where the six member ring ABCDEF has at least one unsaturated bond therein, and wherein neurally effective substance can be an ester of the hydroxyl group on R1 when R1 is CH2, R2 is H and R3 is H. Specifically the ester is an acetate ester. The neurally effective substance is present in 0.1% to 10% by weight of the pesticide. The propellant can be carbon dioxide. The solvent can be an organic solvent. The pesticide for insects and arachnids can contain a solvent and at least one neurally effective substance. The neurally effective substance can be 0.1% to 10% by weight of the pesticide. In preferred embodiments the compositions are an insecticidal aerosol formulation comprising as the active ingredient a member of the group consisting of terpineol, phenyl ethyl alcohol, benzyl acetate, benzyl alcohol, eugenol, cinnamic alcohol and mixtures thereof contained in an aerosol container including a propellant and a solvent.
These and other objects of the present invention will become apparent from a reading of the following specification.
Most insects have an exoskeleton, cuticle or outer shell which has an outer waxy coating. There are microscopic wax canals in the cuticle. The exoskeleton typically comprises multiple body plates joined together by cartilaginous membrane. This thin shell and the waxy coating is the primary protection the insect has to insure the maintenance of its vital body fluids. If an insect loses as little as 10% of these fluids, it will die.
The exoskeleton provides protection against most foreign agents such as pesticidal liquids and powders. For this reason, ingestion is the primary method of delivery for conventional pesticides and may also be a method of delivery of the pesticide of the present invention. However, pests will only ingest certain substances and in small amounts. This imposes limits on the types of usable pesticides and their effectiveness. For instance, insects generally will not ingest fatal amounts of dehydrating pesticide.
The present invention proposes new methods of delivery of a pesticide for insects and arachnids. The pesticide is at least one neurally effective chemical having a functional hydroxyl group in the proximity of a six member carbon ring. The neurally effective chemical, it is believed, is capable of dissolving or in some manner, penetrating the cuticle or waxy coated exoskeleton such that the hydroxyl group of the chemical interacts or binds with a vital substance within the insect or arachnid. This binding is fatal to the insect or arachnid. The neurally effective chemical is dispersed in a carrier which may be a dust, aerosol, emulsion or solvent carrier. The aerosol carrier and the liquid carrier provide an effective media to expose the insect or arachnid to the neurally effective chemical. The dust media provides a carrier to mechanically puncture the exoskeleton and accelerate the interaction between the neurally active chemical and the vital substance within the insect or arachnid. The dust media also is a dehydrating agent which provides another mode for killing the insect or arachnid.
A dust media containing diatomaceous earth, sodium bicarbonate, calcium carbonate and amorphous silica affect most insects very slowly, usually over several hours. Symptomology of exposure to these dusts is a gradual reduction in activity, slow loss of weight, and eventual death. These dusts do not provide rapid or sudden xe2x80x9cknockdownxe2x80x9d.
Diatomaceous earth is a mild abrasive and desiccant. It abraids the cuticle and adsorbs the outer epicuticlar wax layer of several kinds of insects. Some, but not all, insects that lose the protective wax layer under dry conditions succumb within hours from evaporative loss of body water through the remaining integument. Unaffected insects may have a protective basal cement layer in the cuticle that affords additional protection from desiccation. Because some insects may replace surface wax quickly, a mild desiccant such as diatomaceous earth is not effective when the air is moist and has little evaporative power. Even when effective against insects, diatomaceous earth works fairly slowly.
A synergistic effect of calcium carbonate and calcium carbonate with other ingredients is possible, but unlikely. Rapid knockdown or paralysis of insects exposed to heavy deposits of either of these dusts has not been observed.
By their physical nature, several kinds of lightweight dusts with small pore size (i.e. very small particle size) that are not ordinarily considered desiccants may adsorb insect wax, in a similar fashion to diatomaceous earth. Adsorption eventually leads to lethal desiccation if the insect cannot replace the lost cuticular wax.
The rapid knockdown observed with the dust embodiment of the present pesticide is probably the result of an interaction between one or more of the dusts and a nerve-active substance, rather than from desiccation per se. The neurally effective substance may be the nerve-active substance. Once deposited on an insect, some dusts create a xe2x80x9cwater continuumxe2x80x9d between the inside and outside of the insect. Hemolymph, in the form of lipid water liquid crystals, is drawn by the dust to the surface from the interior of the insect through microscopic wax canals in the cuticle. Substances carried in the dust may then pass through the continuum into the insect where they come in contact with nerves bathed by the hemolymph. This process may occur very rapidly.
Another possibility of action is that the dust components facilitate rapid penetration of an active substance through the cuticle. Oily and alcoholic substances such as the neurally effective substance reported herein may readily penetrate thin or untanned portions of cuticle. The dusts may act as a dust diluent for a more xe2x80x9cactivexe2x80x9d compound. Non-sorptive dusts such as diatomaceous earth tend to be effective diluents because they do not bind substances too tightly, thereby making the substance they carry available to the insect surface. Nerves near spiracles or other sensitive sites may be quickly affected, and may result in rapid knockdown, paralysis or death.
Bear in mind that the dust composition of this application, unlike previous dust compositions do not have to be boiled or cooked.
The following substances have been found to be active ingredients, useful as neurally effective substances:
benzyl alcohol
benzyl acetate
phenyl ethyl alcohol
terpineol
cinnamic alcohol
phenol
eugenol.
The neurally active substances have the general structural formula 
where R1 is any of the following:
CH2; C2H4, C3H6, C3H4, C4H8 or C4H4 
where R2 is any of the following:
H, H2, CH3, C2H5, C3H7, C3H5, C4H9 or C4H5 
where R3 is any of the following:
H, H2 or OCH3 
where the six member ring ABCDEF has at least one unsaturated bond therein.
The neurally active substances may also be an ester of the hydroxyl group on R1.
Mixtures of several neurally effective substances have been found to be effective.
The effective concentration of the active ingredient will generally be in the range of 0.01% to 10% and will be the primary active ingredient or function as a synergist. It is to be understood that various known active synergists can be added to the disclosed compositions of this invention to enhance the insecticidal activity of the composition.
The compositions encompassed by this invention will find application for indoor application as well as outdoor application. The composition can be formulated as a xe2x80x9cpet colognexe2x80x9d, for application to pets. An odorless composition is contemplated; as well as compositions formulated to avoid allergic reactions. The floral fragrances contemplated by this invention are limitless.
None of the individual components are identified by the United States Environmental Protection Agency as having active insecticidal properties. All are considered to be inert in and of themselves at the concentration disclosed herein. Thus, the demonstration of toxic effects on pests is considered to be unexpected.
Applicants do not wish to be bound to the theory of neural activity.
If the pesticide of the present invention is liberally administered in the vicinity of the insects, it cannot be avoided by the insects and death is imminent. Moreover, it is impossible for the insects to build an immunity to the composition.
The powder (or dust) embodiment is prepared by processing and/or mixing the crystalline solids [alkali metal bicarbonate (54%-65%), calcium carbonate (27%-35%), amorphous silica (1%-3%) and diatomaceous earth (4%-5%)] in a ribbon blender for approximately five to fifteen minutes to obtain a particle size of approximately 1-100 microns and the neurally effective substance (or substances) is then intimately mixed with the blend of crystalline solids. The amorphous silica known as HiSil(R)233 marketed by Harwick, Akron, Ohio has been used satisfactorily.
The aerosol embodiment is prepared by mixing the active neurally effective substance or substances (1%-7%) with a solvent such as a mixture of paraffin hydrocarbons (50%-95%). Isoparaffinic hydrocarbons sold by Exxon Corporation known as Isopar H, Isopar L and Isopar M have been used satisfactorily but the solvent is not limited to these products. The mix is introduced into an aerosol container together with a propellant such as carbon dioxide, dimethyl ether, propane or a propanebutane mixture (5%-18%). All proportions are by weight.
The liquid formulation or solvent embodiment is prepared by mixing the active neurally effective substance or substances (19%-5) with the isoparaffin hydrocarbon solvent (75%-99%) and placing the mix into a container which can be used for dispensing the liquid.